


Swell

by orphan_account



Category: Merlin (TV)
Genre: Age Play, Alternate Universe - Modern Setting, Impregnation Kink, M/M, Plot What Plot/Porn Without Plot, Roleplay, Sexual Fantasy
Language: English
Status: Completed
Published: 2012-10-29
Updated: 2012-10-29
Packaged: 2017-11-17 07:37:56
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,509
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/549164
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: <blockquote class="userstuff">
              <p>"Please," Merlin begs. "Please." The words come out wet with spit, like he's still gagging for it; drooling, forgetting how to swallow.</p>
<p>Written for this KMM prompt: <i>Arthur is known to be extremely fertile. They both get off on it and talk about it during sex... </i></p>
            </blockquote>





	Swell

**Author's Note:**

> There's no actual mpreg or underage in the fic, it's all part of a shared fantasy.

Merlin is sweaty and out of breath. His blue eyes are dark; the pupils black and huge. Arthur might be holding him down, but right now he's still soaring high up in some stratosphere of his own.

"Please," Merlin begs. "Please." The words come out wet with spit, like he's still gagging for it; drooling, forgetting how to swallow.

"Shh," Arthur says, touching his own dick. It's sore now. When he rubs it the foreskin feels like hungover eyelids; gritty and raw. He would rather put it in Merlin's mouth and feel all that unswallowed spit and come soothe the burning.

But he needs to stick it back in the furnace that's Merlin's arse.

He must come there another time. He's got this funny feeling that he'll die with his next orgasm, but Merlin _needs_ it. Arthur sticks two fingers in the wrecked, swollen snatch of Merlin's once pinprick hole. It should be tight and private, but it's all open now; glistening with lube and come. Arthur's come, Merlin's come that Arthur sucked into his mouth and released into Merlin, holding him open with two fingers.

"I'll fuck you full," Arthur says. "I'll get your pink boy-cunt so full of me you'll be pregnant when I'm done with you." He pauses to touch Merlin's face with a sort of tender menace. His voice sinks as he continues. "That's why you sought me out, isn't it? You'd heard about me. How fertile I am. How I could get _triplets_ on any woman I fucked. You wanted to know if I could do that to you, too. You'd been touching yourself in your bed, fondling your belly, wanting to know what it would feel like with my baby there."

Merlin sobs. It's a dirty, ugly sound, and Arthur wants to hear it again. And _again_.

"Look at you begging for it. Begging me to fuck a baby in you. What would your mummy say about that, Merlin? What would your friends say? Still in school and having got yourself pregnant? Because I could do it. I could get even your skinny body grow full and fat with a tiny Pendragon."

"Yes," Merlin says, choking on the word. "I want that. _Please_ , Arthur. Please, I want you to..." He fondles the hollow expanse of skin underneath his ribs, like he's longing for it to fill, to _swell_. "I want it so much, Arthur. Want them to see... Want them to know you did that to me."

And Arthur creeps up at that, rubs his cock in the trail of Merlin's tears. He wants it to end, wants to lie down at Merlin's side. But he continues, because he knows what Merlin needs.

"You want them to know how you begged me to fuck you without a condom? How you offered your tight, virgin boy-snatch for me to take, behind the bike shed? You want them to know how you whore your way through school? Desperate little scholarship boy, taking it roughly from the rich boys."

"Only you," Merlin whispers pathetically. "Only _you_."

"That's true," Arthur admits. "And never anyone else. Once you've been fucked by Pendragon, you don't want another. I've spoiled you for anyone else."

"Arthur. Oh, Arthur please..." Merlin is bucking his hips now, grinding them, as if pumping himself on an invisible cock.

"They'll send you home in disgrace, Merlin," Arthur says, holding his own cock, trying to stave off his orgasm. "When your belly's too big for your tight little trousers. When your shirt and your blazer won't close around your swollen bump. And you'll have to explain to mummy that you're coming home to have my bastard. That Arthur Pendragon fucked you so good he got you preggers."

Merlin arches his back, as if there's an invisible thread attached to his stomach, pulling him up.

Arthur presses a finger to Merlin's mouth, and Merlin sucks hungrily. When Arthur pulls it out, there's an audible pop. He snakes the wet finger round Merlin's navel. "It's a dimple now, Merlin, but it'll be a like a nipple when you're huge with my child. I'll be able to see it through your clothes when I'll come to see you. I'll feel it in my hand when I'm fucking you. I'll make your bump sway as I take you while your mum makes us tea, downstairs. She'll have to pretend she didn't hear it. Because you'll be so desperate for it you won't care."

He's hardly able to contain himself any longer. He's come three times already, but he's young still, and he'll come again. Somehow.

"Want you inside," Merlin says. "Please, Arthur. Just take me. Fill me with your babies." And Arthur doesn't laugh, because that would kill them both.  


He kneels between Merlin's splayed thighs, presses the swollen head of his cock against the puffy, fucked out maw of a hole that Merlin's offering him. It twitches against him, as if it's trying to gobble Arthur's cock up all on its own.

" _Pleasepleaseplease..._ " Merlin begs, between hyperventilating and biting his plump lower lip.

"Come here," Arthur says. He drags Merlin up into his lap, fumbles a little before he spears him on his cock. They both gasp. It's too much, but they can't stop. Arthur feels the pain of his rubbed raw cock merging with something that's so good. Merlin feels odd inside, like the only grip he has on Arthur is from being all swollen inside, rather than from any clench of muscles. It never fails to amaze Arthur, and it gives him the boost that he needs. 

Suddenly it's easy to lock his arms around Merlin; holding under his knees to lift him, before putting him down again. Fucking Merlin's limp body whether it wants to be fucked or not. And Merlin just holds on to Arthur, eyes closed, weeping. He's the only person Arthur knows who actually _cries_ just because he likes the sex so much. Merlin lets himself be fucked, his mouth as red and open as his arse.

"I'll get a bun in your little oven, Merlin," Arthur gasps, tiring quickly now, after the first mad rush. His arms are burning with lifting Merlin, who isn't as light as he looks. "I'll get fucking twins on you. I'll fuck you so good, sweetheart." He's actually sobbing himself, now. "Come nine months and you'll be rocking my babies. And I'll get you pregnant again as soon as you'll let me near you. I'll never let you out of my bed. That's how much I want you."

Merlin's tightening now, his hole gripping hard even as his head lolls back. "Oh, Arthur... Arthur, Arthur--" There's more, but nothing that makes sense.

"I'm going to show you off, Merlin. I'll tell everyone you're my little _tart_. That you begged for me to stuff that tight boy-cunt of yours. That you gobbled up my swimmers until you got yourself pregnant from it. I'll tell them that when you're pushing a pram with my babies and you're full and fat with another one."

Merlin cries out; spasms in Arthur's arms. And Arthur spills his last drops when Merlin's inner muscles pulse tight around his cock. They fall into a heap afterwards, with Merlin cradling Arthur's head against his bony chest.

*

"I love you," Merlin says and his voice is hoarse. "I thank my lucky stars for you, every day." He presses a tired kiss to the crown of Arthur's head.

It makes Arthur smile. He's too tired to move, so he doesn't. "I love you, too," he says, looking at Merlin's left nipple, instead of at his face. It's a beautiful nipple, small and tight and rightly Arthur's, since half-past two this afternoon. "I wouldn't want another husband."

Merlin chuckles. "Thank God for that. And thank God for summer hols. I was going mad, the last week."

"They get restless," Arthur says, thinking about their pupils. He does, too. Every year, but this year more than ever. Staring out through the window at the sky, wondering if Merlin, in the science block, was thinking about him, too. He's grateful for the fact that they were allowed to stay on when their affair was discovered, as long as they got married.

He wonders if they'd been allowed to stay, had their particular brand of role-playing been known. But then, again. A lot of people are probably harmless closet perverts, just like they are.

"We're so fucked up," he says conversationally, before cheerfully patting Merlin's belly.

"Mmm. I _know_. I could tie you up, next time. If we can find that school tie of yours. And I've always wanted to--"

"You're absolutely shameless, you know that? Here I was, thinking we're perverts, and you're just wallowing in it, like a pig in mud, not the least contrite."

Merlin laughs. He rakes his soft, chemically stained fingers through Arthur's hair. "That's how you like me," he says, all sass.

"Never change," Arthur replies. "Always be my fellow-pervert."

They remain like that, until at long last, they're hungry for something else than sex.


End file.
